KEHUI T-GPS3000 User manual

T-GPS3000 Time Synchroniser
User Manual V1.2
Kehui International Ltd.
2 Centrus, Mead Lane, Hertford
Hertfordshire, SG13 7GX
United Kingdom
Phone: [phone]
Fax: [phone]
Website: http://kehui.com

T-GPS User Manual Version 1.2 | 2
Legal Notices
The copyright of this material belongs to Kehui International Ltd. No company or individual may
extract, copy or translate in any way without the written permission of the copyright owner.
Copyright infringement will be investigated.
This product complies with the design requirements for environmental protection and personal
safety.
This product is a professional instrument specially designed for power cable faults. Please do not use
it for any other purpose. The company assumes no responsibility or loss if it is used for other
purposes.
The safety regulations in this user manual should be strictly adhered to.
The storage, use and disposal of the product should be in accordance with the product manual,
relevant contracts or relevant laws and regulations.
As part of Kehui’s continual product development this product is subject to design or technical
changes without prior notice. When product improvement or technical changes occur, you can check
the information through Kehui International Ltd. website http://www.kehui.com.
Disclaimer: Every effort has been made to make this material complete, accurate, and up-to-date. In
addition, changes are periodically added to the information herein; these changes will be
incorporated into new editions of the publication. Kehui International Ltd reserves the right to make
improvements and/or changes to the product(s) and/or the program(s) described in this document
without notice, and shall not be responsible for any damages, including but not limited to
consequential damages, caused by reliance on the material presented, including but not limited to
typographical errors.
NOTE: Windows is a registered trademark of Microsoft.
Revision history:
Data version
Revision date
Revision reason
Person
1.0
2020.04.15
Document creation
BilKib/TonYip
1.1
2020.04.17
Updated
TonYip
1.2
2020.08.13
Referencing (T-506)
DiaKib
Document number: TGPS_V1.2_UM_EN

T-GPS User Manual Version 1.2 | 3
Table of Contents
1. SAFETY INSTRUCTIONS ..............................................................................................................5
2. PRODUCT OVERVIEW..................................................................................................................6
2.1 Application................................................................................................................................6
2.2 Master Slave Designation ...........................................................................................................6
2.3 Product Features .......................................................................................................................6
2.4 Technical Data Sheet..................................................................................................................7
3. LAYOUT..........................................................................................................................................8
3.1 Front Panel................................................................................................................................8
3.2 Rear Panel.................................................................................................................................9
3.3 Module Configuration ................................................................................................................9
3.4 Outputs.....................................................................................................................................9
3.5 Customisation .........................................................................................................................10
4. MODULE DESCRIPTIONS...........................................................................................................11
4.1 Power Module.........................................................................................................................11
4.2 Signal Input (Antenna)..............................................................................................................11
4.3 IRIG-B Signal Input I Module ................................................................................................12
4.4 IRIG-B Signal Input Module.......................................................................................................13
4.5 Dry Contact Pulse Output .........................................................................................................14
4.6 Serial Port Output Module........................................................................................................15
4.7 Serial Port Output Module II .....................................................................................................16
4.8 TTL Output Module..................................................................................................................17
4.9 RS485 Output Module..............................................................................................................18
4.10 IRIG-B AC Output .....................................................................................................................18
4.11 DCF77 Signal Output Module....................................................................................................19
4.12 Alarm Output Module ..............................................................................................................19
4.13 Ethernet module......................................................................................................................19
4.14 IRIG-B Optical Input Module I ...................................................................................................20
4.15 IRIG-B Optical Input Module II ..................................................................................................20
4.16 Optical Output Module ............................................................................................................21
4.17 Host Interconnect Interface Module..........................................................................................22
4.18 Beidou Signal Input Module......................................................................................................23
4.19 PTP Signal Output Module........................................................................................................24
4.20 Delay Compensation Module....................................................................................................24
4.21 Delay Compensation Output Module ........................................................................................27
5. WORKING PRINCIPLE.................................................................................................................29
i. GPS Receiver........................................................................................................................29
ii. Pulse Generation Circuit .......................................................................................................29
iii. Central processing Unit.........................................................................................................29
iv. RS-232/422/485 Port ............................................................................................................29
v. IRIG-B Port............................................................................................................................29
6. INSTALLATION AND ADJUSTMENT...........................................................................................30
6.1 Delivery Inspection ..................................................................................................................30
6.2 Installation ..............................................................................................................................30
6.3 Master Slave Schemes..............................................................................................................31
6.4 Antenna..................................................................................................................................32

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6.5 Antenna installation.................................................................................................................34
6.6 Location..................................................................................................................................34
7. SETTINGS ....................................................................................................................................35
7.1 Initialisation ............................................................................................................................35
7.2 Front Panel Settings .................................................................................................................35
7.3 Menu Set-up ...........................................................................................................................36
7.4 Output Ports ...........................................................................................................................39
8. MAINTENANCE AND TROUBLESHOOTING..............................................................................40
8.1 Inspection ...............................................................................................................................40
8.2 Troubleshooting ......................................................................................................................40
8.3 Alarms ....................................................................................................................................41
9. TRANSPORTATION.....................................................................................................................41
9.1 Transportation considerations ..................................................................................................41
9.2 Storage conditions, storage period and precautions ...................................................................41
10. UNPACKING AND INSPECTION ..............................................................................................42
APPENDIX A: T-GPS3000 PACKING LIST..........................................................................................42

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1. Safety Instructions
Safety Note:
This user manual is the basic commissioning and on-site operation guide for
the T-GPS3000. All operators of the T-GPS should read the contents of this
manual in advance. The manufacturer of this product is not responsible for any
loss caused by the operator's failure to comply with the operating procedures
of this manual or for violation of the safe working procedures of the operator.
Meaning of the
manual symbols
Important instructions concerning personal safety, operating procedures,
technical safety, etc., are marked with the following symbols:
Symbol
Meaning
Indicates a potential hazard that could result in
serious or fatal injury
Indicates a potential hazard which, if not avoided,
may result in minor personal injury or property
damage.
Indicates that it contains important information and
useful guidance for using this product. Failure to
heed this information may result in the test not
functioning properly.
Indicates that this is a useful guideline based on field
practice.
Use of
accessories:
Please be sure to use Kehui’s spare parts to ensure the safe and reliable use
of this instrument. Using accessories made by other companies will make any
warranty null and void.
Repair and
maintenance:
This instrument must be repaired and maintained by Kehui or an agent
authorised by Kehui. If you have any questions concerning maintenance,
cable fault detection, on-site test consultation, etc., please contact the
company at [email protected].

T-GPS User Manual Version 1.2 | 6
2. Product Overview
2.1 Application
T-GPS3000A Time Synchroniser (T-GPS3000A) is a time synchronisation product that utilises
the Global Positioning System (GPS) to provide a very accurate time reference for the
electric power system.
It combines a GPS receiver with a micro-computer and buffers, to provide a local time source
with a variety of outputs. The format of the output signals is configured to match the
requirements of all available disturbance recorders, sequence of event recorders, travelling
wave fault locators, SCADA systems and other equipment requiring accurate timing.
T-GPS3000A is mainly used in the following applications:
•Providing an accurate time reference for substation equipment such as; Digital Fault
Recorders (DFRs), Sequence of Event Recorders (SERs), Supervisory Control and Data
Acquisition (SCADA) Systems, Relays, and other similar equipment.
•Frequency monitoring comparing the difference between working frequency time and a
standard time reference.
•Measuring phase angles.
•Fault location.
•Relay protection experimentation.
2.2 Master Slave Designation
A T-GPS3000 can be designated as a Master or slave device. It is necessary to have a slave
unit when a single GPS device does not have sufficient outputs to synchronise all the
equipment in the substation, and there is a restriction in the number of antennas that can be
set up. The master unit will synchronise itself to the satellites through the antenna, the
slave(s) will then synchronise to the master.
2.3 Product Features
•1 µS accuracy.
•High reception reliability, immune to adverse field conditions.
•Multiple time code outputs, display of time information via serial port,
•Easy connection to other equipment.

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2.4 Technical Data Sheet
Power Supply
−DC 190-260V
−AC 190-260V, 47Hz-63Hz
Power Consumption:
5W maximum
Data Acquisition Time During Start-Up
−90s maximum typical
−90s maximum with location changes
−45s maximum without location change
−20s maximum after power supply
interruption
Time Accuracy
1 µs
Selectable Output Port Features:
−Pulse output (1PPS/1PPM/ 1PPH):
−Dry output,
−TTL output,
−422/485 output
IRIG-B output
−DC output (TTL output and 422/485
output),
−AC output
DCF77 output
Dry contact
Serial Output
RS232 and RS422/485
Ethernet output
Pulse output
1 PPS, 1PPM and 1PPH (signal pulse width is
200ms)
Configuration:
Master or slave (with correct configuration)
Optional output modules
Dry contact output module (Maximum 12
outputs, 6 modules)
Serial port output module (Maximum 4
outputs, 6 modules)
TTL output module (Maximum 12 outputs, 3
modules –Pulse or IRIG-B)
RS422/ 485 (Maximum 12 outputs, 3
modules –Pulse or IRIG-B)
Ethernet (1 per module, 6 modules)
Environmental
Operating temperature 0oC to 50 oC
Storage temperature -40oC to 50 oC
Dimensions
483mm x 323 x 83mm (19”, 2U rack)
Weight
2 kg

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3. Layout
3.1 Front Panel
The front panel is shown below in Figure 1.
Figure 3.1: Front Panel
⚫Power
The light indicates that the power is on.
⚫Synch. Lost
When the equipment is initially powered-up, this indicator will blink, showing that
the GPS3000A is not synchronised; when the light is off, it indicates that the
system is synchronised. If it blinks during operation, it indicates that the
T-GPS3000A has lost synchronisation.
⚫1PPS Pulse Indicator
If the light is blinking, the system is running correctly.
⚫Time display (LED)
Normally this displays the current time. When the user is operating the
equipment via the front panel, it will display the setting mode.
⚫Buttons
Four buttons are on the front panel, labelled; ‘ITEM’, ‘‘, ‘+’and ‘ENTER’. For
details of their operation, refer to Section 5.4 Front Panel Setting.

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3.2 Rear Panel
Figure 3.2 shows the detailed layout of a fully configured rear panel.
Figure 3.2: Rear Panel
3.3 Module Configuration
The rear panel shows the module configuration, which has 10 blank module positions.
The modules include Power, Outputs and Signal Input (Antenna). The Power Module and
Signal Input (Antenna) Module are mandatory. The different types of output module are
categorised into 7 different types including; dry contact output, TTL output, 485/422 output,
serial output, IRIG-B AC output, DCF77 output and Ethernet output. The dimensions of the
modules are the same, with the exception of the power Module which is installed on
the far left of the rear panel. The others can be installed anywhere on the rear panel.
Customers can order different modules according to their specific application requirements.
3.4 Outputs
There are different signal outputs for different modules which can be changed by changing
jumper or terminals.
•Pulse x 4 includes A, B, C and D groups. These four pulses can be set from the front
panel as 1 pulse per hour (1PPH), 1 pulse per 30 minutes (1PP30M), 1 pulse per 10
minutes 1PP10M, 1 pulse per minute (1PPM), 1 pulse per 30 seconds (1PP30S), 1 pulse
per 10 seconds (1PP10S), 1 pulse per second (1PPS), and event. For the detailed setting
method, refer to Section 7.3 Front Panel Setting. The pulse has three kinds of outputs,
Dry Contact Output, TTL Outputs, and Differential Outputs.
•Serial Port: this provides TXD0 and TXD1 signals. The user can find the signal format
from Section 7.4 Serial Port Output, and the output format from Section 4.7 Serial Port
Output Module.
•IRIG-B Code: this includes IRIG-B DC and IRIG-B AC codes. IRIG-B DC code can be output
from the TTL Output or the Differential Output.

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•DCF77 Code: since this code is used rarely, it only is output from a Dry Contact.
T-GPS has 7 blank modular spaces for the various optional modules. However, for
power consumption reasons, the maximum number of TTL modules is limited to three,
the maximum number of 422/485 is also three and IRIG-B has a maximum of four
modules.
If T-GPS is used as a master, the mandatory modules are the Power Supply module, the
Alarm module, the Antenna module and the Signal Output module (to slave). Leaving 6
blank modules for other options.
If used as a slave, the mandatory modules are two IRIG-B IN modules (for redundancy),
one Power Supply module and one Alarm module. There will again, be 6 blank modules
for other options.
3.5 Customisation
T-GPS3000A is configured using a selection of modules and the outputs can be modified by
adding additional modules as required.
The Dry Contact Output Modules can have maximum of twelve outputs, each can be configured
as 1PPH, 1PP30M, 1PP10M, 1PPM, 1PP30S, 1PP10S, 1PPS, or event outputs.
The Serial Output Modules can have a maximum of four RS232 or RS422 outputs.
The IRIG-B AC Output Module can have maximum twelve outputs, with adjustable amplitude.
The TTL Output Module can have maximum of twelve outputs.
The Differential Output Module can have an RS422 output, pulse output, each can have
maximum of 6 outputs.
Customers should specify the required modules at the time of ordering.

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4. Module Descriptions
4.1 Power Module
The Power Module provides the power supply for the T-GPS3000, the
layout is as the diagram below shows.
A) ON/OFF: to power on or off the GPS.
B) Fuse: 5A fuse is inside (Note: The unit should be powered off when
replacing the fuse).
C) Terminals:
① The terminals marked + and - are for the power supply.
② Earth this device with the terminal marked
4.2 Signal Input (Antenna)
This Module is connected to the antenna, to provide the satellite signal.
Refer to section 6.4 for Antenna installation.

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4.3 IRIG-B Signal Input I Module
Each IRIG-B signal input module accepts two TTL and 422 switchable level
signals.
They can indicate whether they are connected and running normally. Both
level signals are accessed through a DB9 socket. Pins 1 - 4 of the socket are
connected to the first 422 level signal, 1 and 4 are connected to "+" with 2
and 3 connected to "-". Pins 6 -9 are connected to the second 422 level
signal, 6 and 9 are connected to "+", with 7 and 8 connected to "-".Pin 5 is
not used.
In addition, there are four indicators on the panel, from top to bottom:
IRIG-B1, RUN1, IRIG-B2, RUN2.
IRIG-B1 indicates whether the first level signal input is normal. RUN1 indicates whether the first level
signal is running normally. IRIG-B2 indicates whether the input of the second level signal is normal.
RUN2 indicates whether the second level signal is running normally. Each signal can be set by the short
circuit jumper on the board. The specific setting method is as follows:
When the first channel is connected to the TTL level signal, the 1S1 and 1S2 jumpers are connected
as in Figure (a).
When the first channel is connected to the 422 level signal, the 1S1 and 1S2 jumpers are connected
as in Figure (b)
When the second channel is connected to a TTL level signal, the 1S21 and 1S22 jumpers are
connected as in Figure (c).
When the second channel is connected to the 422 level signal, the 1S21 and 1S22 jumpers are
connected as in Figure (d)

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4.4 IRIG-B Signal Input Module
Each IRIG-B signal input module accepts two TTL and 422 switchable level
signals.
They can indicate whether they are connected and running normally. Both
level signals are accessed through a DB9 socket. Pins 1 - 4 of the socket are
connected to the first 422 level signal, 1 and 4 are connected to "+" with 2
and 3 connected to "-". Pins 6 -9 are connected to the second 422 level
signal, 6 and 9 are connected to "+", with 7 and 8 connected to "-".Pin 5 is
not used.
In addition, there are four indicators on the panel, from top to bottom: IRIG-B1, RUN1, IRIG-B2,
RUN2.
IRIG-B1 indicates whether the first level signal input is normal. RUN1 indicates whether the first
level signal is running normally. IRIG-B2 indicates whether the input of the second level signal is
normal. RUN2 indicates whether the second level signal is running normally. Each signal can be set
by the short circuit jumper on the board. The specific setting method is as follows:
When the first channel is connected to the TTL level signal, the 1S1 and 1S2 jumpers are connected
as in Figure (a).
When the first channel is connected to the 422 level signal, the 1S1 and 1S2 jumpers are connected
as in Figure (b)
When the second channel is connected to a TTL level signal, the 1S21 and 1S22 jumpers are
connected as in Figure (c).
When the second channel is connected to the 422 level signal, the 1S21 and 1S22 jumpers are
connected as in Figure (d)

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4.5 Dry Contact Pulse Output
Maximum twelve inputs. Two connectors make a pair and are marked
with ‘c’ and ‘e’ from the top. The left column comprises numbers. 1, 3,
5, 7, 9, 11 and the right one is 2, 4, 6, 8, 10, 12 from top to bottom.
Each output can be set as an A, B, C or D pulse via the jumper on the
PCB. The 8S1 to 8S12 represents outputs 1 to 12.
The detailed setting method is as following:
If 8S1 is in location (a), its output pulse is set to A.
If 8S1 is in location (b), its output pulse is set to B.
If 8S1 is in location (c), its output pulse is set to C.
If 8S1 is in location (d), its output pulse is set to D.
If 8S1 is in location (e), its output pulse outputs the IRIG-B DC signal.
The remaining 11 pairs have the same setting method. Below is the schematic for a dry contact.

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4.6 Serial Port Output Module
The module has up to four serial signals, each routed to a DB9 interface.
Each output can be configured as an RS-232 level or RS-422 level output.
The four-position DIP switch on the board is used to set the baud rate of the
serial port output. When pins 1 to 4 of the DIP switch are turned to "ON",
the status is "1", otherwise it is status "0". Pins 1 and 2 control the baud
rates of "COM1" and "COM2"; Pins 3 and 4 control the baud rates of "COM3"
and "COM4".
The correspondence between the DIP switch pin status and the serial port baud rate is as follows:
1, 2 Pin Status
COM1, COM2
Baud Rate
11
1200
01
2400
10
4800
00
9600
3, 4 Pin Status
COM3, COM4
Baud Rate
11
1200
01
2400
10
4800
00
9600

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4.7 Serial Port Output Module II
The module has up to four serial signals, each routed to a DB9 interface.
Each output can be configured as an RS-232 level or RS-422 level output.
20S1 to 20S4 on the printed board are used to control the outputs of
COM1 to COM4 respectively. The specific setting methods are as follows:
When 20S1 is in the (a) state, COM1 port outputs “PPS2” type pulse signal.
When 20S1 is in the (b) state, COM1 port outputs “PPS1” type pulse signal.
When 20S1 is in the (c) state, COM1 port outputs “TXD2” type pulse signal.
When 20S1 is in the (d) state, COM1 port outputs “TXD1” type pulse signal.
20S2 to 20S4 are set in the same way as 20S1.
Two four-pin DIP switches 20S7 and 20S8 on the board are used to set the serial baud rate of TXD2
and TXD1. When the DIP switch pin is set to "ON", the status changes from “0” to "1". The serial port
baud rate settings are:
1, 2, 3, 4 Pin Status
TXD1, TXD2 Baud
Rate
0000
300
1000
600
0100
1200
1100
2400
0010
4800
1010
9600
0110
14400
1110
19200
0001
38400
1001
56000
0101
57600
1101
115200
Other states
9600

T-GPS User Manual Version 1.2 | 17
4.8 TTL Output Module
A maximum of twelve TTL outputs are provided in each module, each
output can be set to be either a Pulse or an IRIG-B output. The terminals
are in pairs with the upper one being +and lower one -. The left column
is marked 1, 2, 3, 4, 5 and 6; the right column is marked 7, 8, 9, 10, 11
and 12. Each signal can be set with a jumper as pulse A, B, C; pulse A’, B’,
C’ or IRIG-B DC.
A’, B’ and C’ are similar to A, B, and C but have opposite polarities as
shown below
A, B, C A’, B’, C’
TTL output format
Jumper 10S1 to 10S12 controls outputs 1 to 12, the detailed settings are as follows:
If 10S1 is as shown in (a), pair 1 outputs pulse A.
If 10S1 is as shown in (b), pair 1 outputs pulse B.
If 10S1 is as shown in (c), pair 1 outputs pulse C.
If 10S1 is as shown in (d), pair 1 outputs pulse A’, with opposite signal polarity
If 10S1 is as shown in (e), pair 1 outputs pulse B’, with opposite signal polarity
If 10S1 is as shown in (f), pair 1 outputs pulse C’, with opposite signal polarity
If 10S1 is as shown in (g), pair 1 outputs an IRIG-B DC signal.
The setting method for 10S2 to 10S12 is the same as 10S1.

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4.9 RS485 Output Module
A maximum of twelve RS485 outputs are provided in each module,
each output can be set to be either a Pulse or an IRIG-B DC output.
The terminals are in pairs with the upper one being +and lower one -.
The left column is marked 1, 2, 3, 4, 5 and 6; the right column is
marked 7, 8, 9, 10, 11 and 12.
The detailed settings are as follows. Putting the jumper in A, B, C or D
produces a Pulse, and DC provides an IRIG-B DC output.
The signal format for pulse A, B, C and D is as (1) below, however if the output (2) is required, the
connections to “+” and “-” should be reversed.
+4.5V
-4.5V
-4.5V
+4.5V
4.10 IRIG-B AC Output
A maximum of six IRIG-B AC outputs are provided in each module, with
each pair of terminals representing one channel. Output impedance is
600Ω. The amplitude of the six output signals is controlled by the
potentiometer 14R1 which is situated internally. The amplitude
adjustment is 0 –10V.

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4.11 DCF77 Signal Output Module
A maximum of twelve DCF77 outputs are provided in each module. The
output format is as follows:
4.12 Alarm Output Module
Each Alarm Output Module provides 4 outputs. They are; Power Lost
Alarm, Wrong Alarm, Sync. Lost Alarm and IRIG-B Lost Alarm. If this T-
GPS3000 unit is used for slave device, the Sync. Lost Alarm becomes
the IRIG-B 1 Alarm, and the IRIG-B Alarm becomes the IRIG-B 2 Alarm.
The alarm output is a relay with capacity: 220V, 1A.
4.13 Ethernet module
Each Ethernet Module can output one NTP/SNTP signal. There are four
indication lights on the Module:
POWER: Illuminated when the power is on.
RUN: Provides a working condition indication, blinking once per
second to indicate correct operation.
TXD: Data transmit indication, the light will blink when data is
transmitted.
RXD: Data receiving indication, the light will blink when data is
received.

T-GPS User Manual Version 1.2 | 20
4.14 IRIG-B Optical Input Module I
Each module has inputs for two IRIG-B optical signals (used for GPS
extension time synchronisation) and can indicate whether the optical
signals are connected and operating normally. There are four
indicators on the panel, from top to bottom: IRIG-B1, RUN1, IRIG-B2
and RUN2.
IRIG-B1 indicates whether the first optical signal input is present and
RUN1 indicates that it is operating normally. Under normal
conditions, IRIG-B1 flashes quickly and RUN1 flashes more slowly.
IRIG-B2 and Run2 have the same function for the second optical
signal input.
4.15 IRIG-B Optical Input Module II
Each module has inputs for two IRIG-B optical signals (used for GPS
extension time synchronisation) to indicate whether the optical
signals are connected and operating normally. There are four
indicators on the panel, from top to bottom: IRIG-B1, RUN1, IRIG-B2
and RUN2.
IRIG-B1 indicates whether the first optical signal input is present and
RUN1 indicates that it is operating normally. Under normal
conditions, IRIG-B1 flashes quickly and RUN1 flashes more slowly.
IRIG-B2 and Run2 have the same function for the second optical
signal input.
The CPU board reserves 3 groups of interfaces, the first group is 1PPS + serial port message, the
second group is TTL level IRIG-B, and the third group is 1PPS + serial port Message. The main clock
GPS uses the first group, and, if used, Beidou would utilise the third group; the extended clock uses
the first group and the second group, so the "IRIG-B input I module" decodes the IRIG-B signal into
1PPS and serial port messages. The output to the CPU board, "IRIG-B input II module" to identify the
IRIG-B code, if the IRIG-B code is correct, the code is directly output to the CPU board.